The nutrients in an ecosystem are:

1.	continuously lost from an ecosystem
2.	needed as a continuous supply from the outside
3.	recycled time and again indefinitely
4.	continuously synthesized by physical forces

The reservoir is located in the Earth’s crust for:
I. Gaseous type of nutrient cycle
II. Sedimentary nutrient cycle
1. Only I
2. Only II
3. Both I and II
4. Neither I nor II

The function of a reservoir of nutrient cycle is to:
1. synthesize minerals
2. transfer minerals to other ecosystems
3. meet any deficit
4. destroy the unwanted minerals

The dry weight of living organisms is mainly made up of:

The maximum percent of total global carbon is found:
1. in fossil fuels
2. in atmosphere
3. dissolved in oceans
4. in biomass of microbes

The amount of carbon dioxide in the atmosphere is regulated mainly by:
1. the atmosphere itself
2. human activities
3. decomposition by microbes
4. the oceanic reservoir

Carbon dioxide is returned to the atmosphere by all the following except:
1. photosynthesis by the primary producers
2. respiratory activities of producers and consumers
3. decomposers
4. volcanic activity

Deforestation has affected the carbon cycle primarily by:

Regarding phosphorus cycle:

1. Only I is true.
2. Only II is true.
3. Both I and II are true.
4. Both I and II are false.

What is common to Pantoeaagglomerans, Microbacteriumlaevaniformans and Pseudomonas putida?
1. They are phosphate solubilising bacteria
2. They are all denitrifiers
3. They are genetically modified to fix atmospheric nitrogen
4. They are source of antibiotics effective against MRSA